Inverter circuits which are well known from the prior art are a full bridge type inverter circuit, a half bridge type inverter circuit, and a center tap push pull type inverter circuit. Illustrations of the concepts of these inverter circuits are shown in FIG. 5.
The full bridge type has a structure in which switching elements S1 through S4 are connected in a bridge pattern, and a power supply V is connected across the bridge. The switching elements S1 and S4, and the switching elements S2 and S3, are alternately turned ON and OFF, so that an alternating current flows in a primary winding P of an output transformer (refer to Patent Document #1).
In the half bridge type, switching elements S1 and S2 are respectively connected to voltage sources C1 and C2, and the power supply V is connected between these voltage sources C1 and C2. The switching elements S1 and S2 are alternately turned ON and OFF, so that an alternating current flows in the primary winding P (refer to Patent Document #2).
In the center tap push pull type, the power supply V is connected to a center tap of the primary winding P, which is connected between switching elements S1 and S2. The switching elements S1 and S2 are alternately turned ON and OFF, so that an alternating current flows in the primary winding P (refer to Patent Document #3).
Moreover snubber circuits which include snubber capacitors and snubber resistors are usually provided to these inverter circuits, so that surge voltages are not applied to their switching elements.
patent document #1: Japanese Laid-Open Patent Publication 2007-151225;
patent document #2: Japanese Laid-Open Patent Publication 2005-279774;
patent document #3: Japanese Laid-Open Patent Publication 2001-112253.